en_tn/deu/03/18.md

I commanded you at that time

Moses is speaking to the tribe of Reuben, the tribe of Gad, and half of the tribe of Manasseh who just received their land. He is telling them that they must go help the other Israelites conquer the rest of the land God promised them.

your brothers, the people of Israel

AT: "your fellow Israelites"